Overview
EN ISO 8745:2025 - Fasteners: Taper grooved pins with half‑length progressive grooves specifies the characteristics of taper grooved pins (with the close end at the insertion side) made in steel and stainless steel, nominal diameters 1 mm to 25 mm. Published by CEN and aligned with ISO 8745:2025, this fasteners standard defines geometry, dimensional tolerances, material options and marking/packaging requirements for grooved pins designed for positioning, guiding and permitting relative rotation of assembled parts.
Key topics and technical requirements
- Product scope: Taper grooved pins with half‑length progressive grooves (three grooves, open at the end opposite insertion).
- Dimensions & tolerances: Detailed size tables (1–25 mm) and standard lengths; groove length = l/2 with specified tolerances depending on pin length. Rounded (RN) or optional chamfered (CH) ends. Groove and spacing geometry (e.g., 120° between grooves ±20°; groove angle reference 70°).
- Expanded diameter and straightness: Control of expanded diameter (d) and axial straightness (t) is specified in the referenced general standard ISO 13669. For coated pins, dimensions apply prior to coating.
- Materials & grades: Steel and stainless steel (stainless grades A2, A4, C1 and F1 added). Other materials (hardened steels, brass, aluminium) allowed by agreement. Mechanical and physical properties referenced to ISO 13669 and ISO 3506‑6.
- Mechanical behaviour: Pins are intended to provide easy installation (tapered shape) and medium pull‑out resistance through elastic fit behaviour-suitable for positioning/guiding and allowing relative rotation.
- Labelling & designation: Packaging and designation rules are included (Clause 8), plus acceptance/inspection references (ISO 3269, ISO 1891‑4).
- Standards management: Supersedes EN ISO 8745:1997; technical changes include updated diameters, added stainless grades and clarified tolerances.
Applications and users
- Typical applications: Precision assemblies, locating and guiding components, rotational pivots where medium pull‑out resistance and easy insertion are required - e.g., mechanical assemblies, instrumentation, automotive subassemblies, and small machinery.
- Who uses this standard: Fastener manufacturers, component designers, mechanical engineers, quality and inspection teams, procurement/specification writers, and assembly process engineers who need consistent dimensions, materials and acceptance criteria for taper grooved pins.
Related standards
EN ISO 8745:2025 is a practical, dimensional and material specification for designers and manufacturers specifying taper grooved pins, ensuring interchangeability, reliable positioning and predictable pull‑out behaviour across applications.
